Japanese fishermen concern for safety after yesterday's intrusion Chinese vessels into the disputed water in East China Sea.

Following the intrusion of six Chinese surveillance ships into Japan's territorial waters around the Senkaku Islands in Ishigaki, Okinawa Prefecture, yesterday, local fishermen and others expressed concern, while the Japan Coast Guard said the incident must be handled calmly.

The JCG headquarters in Tokyo was informed by its 11th regional branch that one of the six Chinese ships entered Taishoto island's contiguous zone shortly before 5 a.m. A number of senior JCG officials were then called to the headquarters.

"We have to deal with [the incident] in a calm manner," a senior JCG official said.

In the wake of the government's nationalisation of three of the Senkaku Islands, it was reported Tuesday that surveillance ships were dispatched to the islands. The JCG stepped up its surveillance and prepared for the ships' possible entrance into the contiguous zone or territorial waters.

"When there are intrusions into the nation's territorial waters or land, it's the state's mission to protect [people's] lives and assets as well as ensure the safety of fishermen. It's a diplomatic issue, and we have no choice but to leave it to the government," Nakaima said.

Kameichi Uehara, 50, head of the Yaeyama fishermen's association in Ishigaki, was concerned about the possible impact on fishing operations near the islands, saying, "We shouldn't make a big deal out of it."

"We can just see what happens. We hope the government makes all possible diplomatic efforts to protect the nation's territory," Uehara added.

Travel agencies also are worried their businesses could be adversely affected if tensions grow.

A public relations official of H.I.S. Co.'s Fukuoka branch said: "Trips to China have decreased by about 10 per cent in the last couple of weeks compared with last year. We've heard other agencies are facing cancelations of school trips and group tours [to China.] We don't think there will be any problems with China trips, but we're worried rumours might adversely affect the situation."

HTB Cruise Co., which launched services between Nagasaki and Shanghai in late February, said reservations have not increased even though China's National Day holidays are later this month.

A spokesperson of the company said, "Sales should be increasing now, and we hope the Senkaku issue will not have a negative impact."